//! Base HTTP client for makima API.

use reqwest::Client;
use serde::{de::DeserializeOwned, Serialize};
use thiserror::Error;

/// API client errors.
#[derive(Error, Debug)]
pub enum ApiError {
    #[error("HTTP request failed: {0}")]
    Request(#[from] reqwest::Error),

    #[error("API error (HTTP {status}): {message}")]
    Api { status: u16, message: String },

    #[error("Failed to parse response: {0}")]
    Parse(String),
}

/// HTTP client for makima API.
pub struct ApiClient {
    client: Client,
    base_url: String,
    api_key: String,
}

impl ApiClient {
    /// Create a new API client.
    pub fn new(base_url: String, api_key: String) -> Result<Self, ApiError> {
        let client = Client::builder()
            .build()?;

        Ok(Self {
            client,
            base_url: base_url.trim_end_matches('/').to_string(),
            api_key,
        })
    }

    /// Make a GET request.
    pub async fn get<T: DeserializeOwned>(&self, path: &str) -> Result<T, ApiError> {
        let url = format!("{}{}", self.base_url, path);
        let response = self.client
            .get(&url)
            // Send both headers - server will try tool key first, then API key
            .header("X-Makima-Tool-Key", &self.api_key)
            .header("X-Makima-API-Key", &self.api_key)
            .send()
            .await?;

        self.handle_response(response).await
    }

    /// Make a POST request with JSON body.
    pub async fn post<T: DeserializeOwned, B: Serialize>(
        &self,
        path: &str,
        body: &B,
    ) -> Result<T, ApiError> {
        let url = format!("{}{}", self.base_url, path);
        let response = self.client
            .post(&url)
            // Send both headers - server will try tool key first, then API key
            .header("X-Makima-Tool-Key", &self.api_key)
            .header("X-Makima-API-Key", &self.api_key)
            .header("Content-Type", "application/json")
            .json(body)
            .send()
            .await?;

        self.handle_response(response).await
    }

    /// Make a POST request without body.
    pub async fn post_empty<T: DeserializeOwned>(&self, path: &str) -> Result<T, ApiError> {
        let url = format!("{}{}", self.base_url, path);
        let response = self.client
            .post(&url)
            // Send both headers - server will try tool key first, then API key
            .header("X-Makima-Tool-Key", &self.api_key)
            .header("X-Makima-API-Key", &self.api_key)
            .send()
            .await?;

        self.handle_response(response).await
    }

    /// Make a PUT request with JSON body.
    pub async fn put<T: DeserializeOwned, B: Serialize>(
        &self,
        path: &str,
        body: &B,
    ) -> Result<T, ApiError> {
        let url = format!("{}{}", self.base_url, path);
        let response = self.client
            .put(&url)
            // Send both headers - server will try tool key first, then API key
            .header("X-Makima-Tool-Key", &self.api_key)
            .header("X-Makima-API-Key", &self.api_key)
            .header("Content-Type", "application/json")
            .json(body)
            .send()
            .await?;

        self.handle_response(response).await
    }

    /// Make a DELETE request.
    pub async fn delete(&self, path: &str) -> Result<(), ApiError> {
        let url = format!("{}{}", self.base_url, path);
        let response = self.client
            .delete(&url)
            .header("X-Makima-Tool-Key", &self.api_key)
            .header("X-Makima-API-Key", &self.api_key)
            .send()
            .await?;

        let status = response.status();
        if !status.is_success() {
            let body = response.text().await.unwrap_or_default();
            return Err(ApiError::Api {
                status: status.as_u16(),
                message: body,
            });
        }

        Ok(())
    }

    /// Handle API response.
    async fn handle_response<T: DeserializeOwned>(
        &self,
        response: reqwest::Response,
    ) -> Result<T, ApiError> {
        let status = response.status();
        let status_code = status.as_u16();

        if !status.is_success() {
            let body = response.text().await.unwrap_or_default();
            return Err(ApiError::Api {
                status: status_code,
                message: body,
            });
        }

        let body = response.text().await?;

        // Handle empty responses
        if body.is_empty() || body == "null" {
            // Try to parse empty/null as the target type
            serde_json::from_str::<T>("null")
                .or_else(|_| serde_json::from_str::<T>("{}"))
                .map_err(|e| ApiError::Parse(e.to_string()))
        } else {
            serde_json::from_str::<T>(&body)
                .map_err(|e| ApiError::Parse(format!("{}: {}", e, body)))
        }
    }
}